What Fluids Are Used In A Car?


The question has come up “What fluids are used in a car” So I thought I would take a few minutes and try to briefly cover automotive fluids. Other related questions that I will try to answer are “What color are the fluids in my car” and “Where do you put water in a car”.


Becoming familiar with these fluids could help save money and possibly prevent an expensive repair by just spending a few minutes once every week or two checking your cars fluid levels and conditions. So I will list these in the order I feel is most important for safety and longevity.


#1) Engine Oil

To check the engine oil; Once the engine is warm and turned off, locate the dipstick which will usually be yellow in color (although not always), Pull the stick, wipe it off with a towel and reinsert it into the dipstick tube and remove again. Now check the level against the hash marks to determine if it is full. Reinsert and add if needed. If you need to add, know that oil is not just oil, there are very specific requirements for newer vehicles. Check your owner’s manual for the specific oil requirements for your car before adding. Please notice in the picture or the right that the new oil is light gold in color and full, while the oil on the left is low, dirty and in need of service.




#2) Engine Coolant

Also known as antifreeze. Always remember; NEVER open a hot cooling system as you will most likely get burnt. Coolant keeps your engine from overheating and also prevents freezing during cold weather. Overheating can cause catastrophic engine damage to you engine, so in terms of importance it is right there with engine oil. Most newer cars incorporate the coolant overflow bottle/reservoir into the closed cooling system and it will usually be found on the passenger side of the car under the hood. This is most often just a visual check for correct level. Old style “green” antifreeze is good for up to 2 yrs. Other colors indicate long life fluid. Many new cars have very specific needs for coolant also and will usually be a different color, For example “GM Dexcool” is orange in color while Toyota could be pink or blue. Always check the owner’s manual for correct type before adding.



#3) Transmission fluid

Checking the transmission fluid is usually like checking the engine oil, done with a dipstick. This is most often found at the back end of the engine near the transmission and will often have a red handle. Transmission fluid is usually light transparent red in color. Some exceptions are new Ford and Toyota fluids which will be very dark/ black even when new. Again, check owner’s manual for correct fluid.


#4) Brake Fluid

The brake master cylinder will most often have the reservoir mounted directly on top of it however it can be mounted remotely in some cases. It will usually be found on the driver’s side of the car mounted to the booster at the firewall. On most newer cars the reservoir will be semi-transparent and allow for a quick visual inspection. For more on brake fluid see our blog entry titled “Is it necessaryto flush brake fluid




#5) Power Steering Fluid

Locate the reservoir which may be mounted to the pump or remotely mounted. Remote reservoirs are usually somewhat transparent allowing you to see the fluid level. Most Power Steering fluid is clear in color while some of the older domestic vehicles can use transmission Dexron 3/Mercon fluid which is light pink / red.  


#6) Windshield Washer Fluid

This reservoir is usually mounted in the front of the engine bay on one side or the other of the radiator. This can lead to occasional mistakes, so make sure to read the lid and verify that you are looking at washer fluid and nor engine coolant. “Can you use any type of windshield washer fluid”, the answer is most often yes. However if you live in a cold climate you will need to make sure if includes an antifreeze as well. Water can be used in a pinch but often just causes smearing which can make the situation worse. Do not use dish soap in water. These reservoirs will often hold as much as a gallon of fluid.


#7) Air Conditioner Refrigerant

This is one best left to the professionals with the training and equipment to service A/C systems.

If you are curious to know if the system has a proper charge, the safest ways to check is by placing a thermometer in the duct, start the engine and turn the A/C to Max A/C and allow it to run for several minutes and check the duct temperature. This should be somewhere between 28-38 degrees F. Note that it will change with ambient temperature.



I hope this helps to understand what fluids are in your vehicle as well as how to check them and what color they are.

Should you need help or service with your cars fluids, London’s Automotive, Inc. is always glad to be of service. Feel free to stop by or give us a call.